Configuration parameter details: | |
Name | $smwgValueLookupFeatures |
Description | Sets which value lookup features should be served from value lookup cache |
Default setting | See below |
Software | Semantic MediaWiki |
Since version | |
Until version | still available |
Configuration | Cache · Experimental |
Keyword | caching · object cache · performance · query performance · query lookup cache · query lookup · experimental |
$smwgValueLookupFeatures
is a configuration parameter that sets which value lookup features should be served from value lookup cache to allow for a more fine grained tuning depending on the size available for the cache of the different "ValueLookupStore" interfaces. The configuration parameter was introduced in Semantic MediaWiki 2.3.0Released on 29 October 2015 and compatible with MW 1.19.0 - 1.25.x.1 and removed in Semantic MediaWiki 3.0.2Released on 11 April 2019 and compatible with MW 1.27.0 - 1.31.x.2 since it has not shown the expected improvements. Instead the internal prefetch lookup feature will be used.3
Default setting[edit]
$smwgValueLookupFeatures => SMW_VL_SD | SMW_VL_PL | SMW_VL_PV | SMW_VL_PS;
This means that the value lookup is always done from the defined value lookup cache backend for all features.
Available options[edit]
SMW_VL_SD
– corresponds to "Store::getSemanticData
"SMW_VL_PL
– corresponds to "Store::getProperties
"SMW_VL_PV
– corresponds to "Store::getPropertyValues
"SMW_VL_PS
– corresponds to "Store::getPropertySubjects
" (mainly involved when generating queries)
Changing the default setting[edit]
To modify the setting to this configuration parameter, add one of the following lines to your "LocalSettings.php" file after the enableSemantics()
call:
- Removing the "getSemanticData" feature
$smwgValueLookupFeatures = SMW_VL_PL | SMW_VL_PV | SMW_VL_PS;
or alternatively remove the feature flag from the existing definition of the configuration parameter like e.g.
$smwgValueLookupFeatures = ( $smwgValueLookupFeatures & ~SMW_VL_SD );
- Disable all value lookup features
$smwgValueLookupFeatures = 0;
See also[edit]
- Help page on configuration parameter
$smwgExperimentalFeatures
Sets experimental features - Help page on configuration parameter
$smwgValueLookupCacheType
Sets a separate cache type for the object cache when requesting value lookups from the database - Help page on configuration parameter
$smwgValueLookupCacheLifetime
Sets the cache lifetime of the value lookup cache until it is being invalidated
- Caching in general
- Help page on caching
- Help page on configuration parameter
$smwgMainCacheType
Sets which object cache Semantic MediaWiki should use to track temporary changes - Help page on configuration parameter
$smwgCacheType
Sets which object cache Semantic MediaWiki should use to track temporary changes
References
- ^ Semantic MediaWiki: GitHub issue gh:smw:1116
- ^ Semantic MediaWiki: GitHub pull request gh:smw:3808
- ^ Semantic MediaWiki: GitHub issue gh:smw:3722
- ^ Bitwise Operators to use parentheses to ensure the desired precedence ...